As is known, a digital signal is composed of a succession of sampled values. The sampled values, separated from one another in time by the sampling period, are situated at regular intervals along the operating course of the sampled continuous-time signal. Thus a sampled value will not necessarily be situated at the maximum of the sampled continuous-time signal. For a variety of applications, it is necessary to determine or estimate from the sampled sequence the maximum of the sampled continuous-time signal. One possible application, for example, is in an automatic gain control (AGC) in which a preamplifier arranged ahead of the analog/digital converter is switched on or off as a function of the level of the signal to be sampled, or is adjusted with respect to its gain factor. This procedure increases measuring dynamics and reduces quantification noise, by making better use of the range of values of the analog/digital converter. So that the preamplifier can be switched on or off, or adjusted, as a function of signal amplitude, the maximum of the sampled signal must be estimated. The method and device of the invention serve this purpose.